The dataset as described in the paper linked below-

"In the initial evaluation of our system, we use three voices; one English male and female (M1, F1), and one Spanish female (F2). The recordings consist of short sentences sung at a single pitch and an approximately constant cadence. The sentences were selected to favor high diphone coverage. For the Spanish dataset there are 123 sentences, for the English datasets 524 sentences (approx. 16 and 35 minutes respectively, including silences). Note that these datasets are very small compared to the datasets typically used to train TTS systems, but this is a realistic constraint given the difficulty and cost of recording a professional singer"